Subtle Freckles #89
 Light  CC BY-SA 3.0

This is so subtle: We’re talking 1% opacity. Get your squint on!

Source Atle Mo

 More Textures
Background pattern 230 (colour 3) #2303
 Green  CC 0

To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.

Source Firkin

Double Lined #51
 Stripes  CC BY-SA 3.0

Horizontal and vertical lines on a light gray background.

Source Adam Anlauf

Colorful Floral Background 2@2X #488
 Dark  CC 0

Colorful Floral Background 2

Source GDJ

Background pattern 328 (colour 5) #1797
 Blue  CC 0

To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i

Source Firkin

Fire diamond #2488
 Diamond  CC 0

U.S.-based National Fire Protection Association standard fire diamond for flagging risks posed by hazardous materials. The red diamond has a number 0-4 depending on flammability. The blue diamond has a number 0-4 depending on health hazard. The yellow has a number 0-4 depending on reactivity. the white square has a special notice, e.g OX for oxidizer.

Source Firkin

Retro Circles Background 5 #424
 Noise  CC 0

Retro Circles Background 5

Source GDJ

Background pattern 289 (colour 2) #1936
 Red  CC 0

To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Background pattern 3 #222
 Noise  CC 0

A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.

Source Firkin

Zodiac sign symbol background #1927
 Red  CC 0

Just the symbols of the signs of the zodiac distributed in a chequer board-like pattern

Source Firkin

Kaleidoscope Prismatic Abstract No Background #387
 Noise  CC 0

Kaleidoscope Prismatic Abstract No Background

Source GDJ

Carbon Fiber Big #326
 Carbon  CC BY-SA 3.0

Bigger is better, right? So here you have some large carbon fiber.

Source Factorio.us Collective

Retro Circles Background 8 #435
 Dark  CC 0

Retro Circles Background 8

Source GDJ

Background pattern 21 #205
 Light  CC 0

A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.

Source Firkin

Real Carbon Fiber@2X #287
 Carbon  CC BY-SA 3.0

Carbon fiber is never out of fashion, so here is one more style for you.

Source Alfred Lee

Lead glass tile #2048
 Colorful  CC 0

Mostly just mucked about with the colours and made one of the paths in the lead frame opaque. The glass remains transparent.

Source Firkin